This invention relates to intravascular filtering apparatus and methods in general, and more particularly to apparatus and methods for filtering and irreversibly entrapping embolic debris from the vascular system during an intravascular or intracardiac procedure.
Intracardiac and intravascular procedures, whether performed percutaneously or in an open, surgical, fashion, may liberate particulate debris. Such debris, once free in the vascular system, may cause complications including vascular occlusion, end-organ ischemia, stroke, and heart attack. Ideally, this debris is filtered from the vascular system before it can travel to distal organ beds.
Using known filter mechanisms deployed in the arterial system, debris is captured during systole. There is a danger, however, that such debris may escape the filter mechanism during diastole or during filter removal. Apparatus and methods to reduce debris escape during diastole or during filter removal may be desirable to reduce embolic complications.
An object of the invention is to provide a filtering mechanism that irreversibly entraps debris therein.
Another object of the invention is to provide a filtering mechanism that permanently captures debris from the intravascular system of a patient.
A further object of the invention is to provide a filtering mechanism with greater ability to collect debris in the intravascular system of a patient to decrease the number of complications attributable to such debris.
Another further object of this invention is to provide a filter holding mechanism suitable to be secured to a retractor used to create access to the heart and surrounding structures during heart surgery procedures.
A still further object is to provide a method for using a filtering mechanism in the intravascular system of a patient to permanently capture debris therefrom.
Another still further object of the present invention is to provide a method for introducing a filtering device in the aorta downstream of the aortic valve to restrict the passage of emboli while allowing blood to flow through the aorta during cardiovascular procedures, and to entrap debris collected in the filter so as to prevent its escape during cardiac diastole or during manipulation, repositioning or removal of the device from the aorta.
With the above and other objects in view, as will hereinafter appear, there is provided apparatus for debris removal from the vascular system of a patient, the apparatus comprising: a filtering device having a proximal side and a distal side, the filter being sized to allow blood flow therethrough and to restrict debris therethrough and the filter having a first given perimeter, wherein blood flow in a first direction passes from the proximal side to the distal side of the filtering device; an entrapment mechanism having a proximal side and a distal side, the entrapment mechanism forming a selective opening to allow debris and blood flow passage in the first direction from the proximal side to the distal side therethrough, the selective opening having a restriction mechanism to prevent debris passage in a second direction opposite to the first direction, the selective opening having a second given perimeter, the first given perimeter and the second given perimeter being deployed within the vascular system so as to form a chamber between the distal side of the entrapment mechanism and the proximal side of the filtering device, wherein the entrapment mechanism allows blood flow and debris to pass therethrough in the first direction, the filtering device allows blood flow to pass therethrough in the first direction, the restriction mechanism prevents debris from passing back through the selective opening in a second direction opposite to the first direction and the chamber contains the debris received through the entrapment mechanism so as to prevent the escape of the debris therein by the filtering device in the first direction and the restriction mechanism in the second direction.
In accordance with another further feature of the invention there is provided a method for filtering and entrapping debris from the vascular system of a patient, the method comprising: providing apparatus for filtering and entrapping debris from the vascular system of a patient, the apparatus comprising: a filter device being sized to allow blood flow therethrough and to restrict passage of debris therethrough, and the filter device having a first given perimeter, a proximal side and a distal side; and wherein the filtering device captures debris carried in a first direction of blood flow from the proximal side to the distal side thereof on the proximal side of the filter device; an entrapment mechanism having a proximal side and a distal side, the entrapment mechanism including a selective opening to allow passage of blood and debris therethrough, the selective opening being configured to allow passage of blood and debris carried therein therethrough in the first direction of blood flow from the proximal side to the distal side of the entrapment mechanism, the selective opening having a restriction mechanism to prevent debris passage from the distal side to the proximal side of the entrapment mechanism in a second direction opposite to the first direction, the selective opening forming a second given perimeter, and the first given perimeter and the second given perimeter being deployed witin the vascular system so as to form a chamber between the distal side of the entrapment mechanism and the proximal side of the filtering device; wherein the entrapment mechanism allows blood and debris carried therein therethrough in the first direction of blood flow, the filtering device allows blood therethrough in the first direction of blood flow, and the restriction mechanism prevents debris back through the selective opening in the second direction of blood flow opposite to the first direction of blood flow such that the chamber entraps the filtered debris received therein for debris removal from the vascular system of the patient; inserting the apparatus into the vascular system of the patient; allowing blood and debris carried therein to flow through the entrapment mechanism, and into the chamber; and removing the apparatus from the vascular system of the patient.
The above and other features of the invention, including various novel details of construction and combinations of parts and method steps will now be more particularly described with reference to the accompanying drawings and pointed out in the claims. It will be understood that the particular devices and method steps embodying the invention are shown by way of illustration only and not as limitations of the invention. The principles and features of this invention may be employed in various and numerous embodiments without departing from the scope of the invention.